New 2, 5-dibenzoxazolyl-thiophene derivatives



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United States Patent The present invention provides new, valuable 2:5-dibenzoxazolyl-thiophene compounds corresponding to the general formula 1 in which X stands for a free or neutralized carboxyl group (-COO cation) or a functionally converted carboxyl group, and Z and Z are identical or different,

alkylene-X each representing a hydrogen atom or a methyl group.

The alkylene group in the radical -alkylene-X of the Formula 1 may be linear or branched and contain, for example, up to 12 carbon atoms. Suitable functionally converted carboxyl groups are carboxylic acid halide groups, more especially the acid chloride group carboxylic acid ester groups, preferably carboxylic acid alkyl ester groups, the carboxylic acid nitrile group CN, carbonamide groups (--CONH and amide groups organically substituted at the nitrogen) and carboxylic acid hydrazide groups.

From among the new 2:5-dibenzoxazolyl-thiophene compounds of the composition defined above there may be mentioned, for example, those of the formula N\ '/N\ ci a. y

in which X, stands for a free or neutralized carboxyl group of the formula -COO cation, a carboxylic acid nitrile group, a carboxylic acid alkyl ester group, a carbonarnide group or a carboxylic acid hydrazide group, the alkylene group being of low molecular weight, that is to say containing 1 to 6 carbon atoms and correspending, for example, to one of the formulae X -alkylene alkylene-X and Z and Z may be identical or different, each representing a hydrogen atom or a methyl group. Among the aforementioned 2:5-dibenzoxazolyl-thiophene compounds those deserve special mention which correspond to the formula Z1 Z1 N N Xq-CH2-CH GHQ-CHg-Xg in which X represents one of the groups --COOH, CN, COOR (where R is an alkyl radical with 1 to 4 carbon atoms) or a carbonamide group or a carboxylic acid hydrazide group, and Z andZ may be identical or ice where Z and Z may be identical or different, each representing a hydrogen atom or a methyl group-or with a functional derivative of such a dicarboxylic acid, using an ortho-hydroxyaminobenzene of the formula X alkylene where X is a free or neutralized carboxyl group or a functionally converted carboxyl group and, if desired, converting in the resulting product a free carboxyl group into a functionally modified carboxyl group or hydrolyzing a functionally converted carboxyl group or converting it into another functionally modified carboxyl group.

Particularly suitable starting materials are, for example, the ortho-hydroxyaminobenzenes of the formula X -alkylcn NHr in which the alkylene group contains 1 to 12, preferably 2, carbon atoms and X represents for instance a carboxylic acid nitrile, carbonamide or carboxylic acid ester group. Ortho-hydroxyaminobenzenes of. this kind can be prepared in known manner by coupling a diazonium salt, for example diazotized aniline, with a hydroxy compound of the formula X -alkyl'ene where X has the above meaningand splitting the resulting azo compound by reduction with, for example,

sodium hydrosulfite, to the corresponding amine.

The further starting material used is a dicarboxylic acid of the Formula 4, for example thiophene-2:5-dicarboxylic acid, or 3:4-dimethyl-thiophene-2:S-dicarboxylic acid or monomethyl-thiophcne-Z:S-dicarboxylic acid, or a functional derivative of one of these dicarboxylic acids,

.for example, a dicarboxylic acid dichloride.

The reaction of the two components may be carried out without intermediate isolation by heating to an elevatedtemperature, for example to 260 C., advantageously in an inert gas, for example in a current of nitrogen, it. being preferable to conduct the reaction in the presence of a catalyst. Suitable catalysts are, for example, boric acid, zinc chloride, para-toluenesulfonic acid, also polyphosphoric acids including pyrophosphoric acid. When the reaction, is performed with boric 'acid as catalyst, it is of advantage to use it in' an amount of about 0.5 to 5% referred to the totalweight of the reaction batch. It is also possible to use concomitantly high-boiling polar organic solvents such, for example, as dimethyl formamide and aliphatic (if desired etherified) hydroxy defined above display in the dissolved or finely dispersed resin lacquers, alkyd resin lacquers, cellulose ester lacfibers, for example of cellulose esters such as cellulose propionate or acetylcellulose (cellulose diacetate or cel- The present process may also be performed in two lulose triacetate; acetate rayon), polyamides (for examsteps by first condensing 1 molecular proportion of a ple nylon), polyesters (for example Dacron or Terylene) dicarboxylic acid of the Formula 4 or of a functional 5 or fibers of polyolefines such as polyethylene and polyderivative of the dicarboxylic acid, more especially of a propylene, of polyvinyl chloride or polyvinylidene chlodicarboxylic acid dichloride, with 2 molecular proporride, as well as films, foils, tapes or shaped structures tions of ortho-hydroxyaminobenzene in the presence of made from these materials or other materials such as an organic solvent such as toluene, a xylene, chlorobenpolystyrene, polyvinyl alcohol or polyvinyl esters of orzene or nitrobenzene at an elevated temperature, followed ganic acids, for example polyvinyl acetate. by conversion of the resulting acyl compound into the For optically brightening by the present process syndibenzoxazole at an elevated temperature, preferably in th tie fiber whjeh may be present in the form f staple the presence of a catalyst. fibers or continuous filaments, in the raw state, in the A 2:S-dibenzoxazolyl-thiophene compound of the forform of hanks or fabricsit is of advantage to use an mula aqueous medium in which the selected thiophene com- (3) pound is suspended. If desired there may be concomitantly used in the treatment dispersing agents such, for

compounds, for example propylene glycol, ethylene glycol monoethyl ether or diethylene glycol diethyl ether.

N N XTCHTCH, GHFCHTX, example, as soaps, polyglycol ethers of fatty alcohol, l L fatty amines or alkylphenols, cellulose sulfite waste liquor or condensation products of formaldehyde with option- O O ally alkylated naphthalenesulfonic acid. It has proved particularly advantageous to work in a neutral, weakly alkaline or acid bath. Likewise it is of advantage to perform the treatment at an elevated temperature from about 50 to 100 C., for example at the boiling temperature of the bath or in its vicinity (at about 90 C.). The improvement according to the invention may also be performed in a solution in an organic solvent.

where X represents a carboxylic acid alkyl ester group or a tree carboxyl group-can be prepared, for example by condensing thiophene-2:5-dicarboxylic acid dichloride 0 1n the molecular ratio of 1:2, in the presence of an organic solvent such as toluene, with an ortho-hydroxyaminobenzene of the formula (9) R0 0 The new thiophene derivatives to be used in the present process may also be added to or incorporated with the OH materials before or during their shaping. Thus for instance they may be added to the moulding composition (R alkyl) used in the manufacture of films, foils, tapes or shaped then converting the resulting acylamino compound of the StYuctuYe '5, 9 they y be Y 0r y P formula in the spinning mass pr1or to the spmnmg operation. The

in the presence of boric acid and of an organic solvent new thiophene derivatives may also be added to the reacat an elevated temperature into the dibenzoxazole comtion batch before or during the polycondensation yielding, pound of the formula for example polyam1des, or to the polymerization batches and, if desired, hydrolyzing the carboxylic acid alkyl ester before or during the polymerization of monomers, for groups in known manner. The conversion of free carexample vinyl acetate. boxyl groups into neutralized carboxyl groups (ammo- The amount of thiophene derivativeto be used accordnium salts, metal salts or amine salts) or into functioning to the invention, referred to the weight of the material ally modified carboxyl groups likewise follows the usual to be optically brightened, may vary within wide limits. practice. Thus, for example, nitrile groups may be Even a very Small a 0unt1n some cases as little as hydrolyzed, or free carboxyl groups esterified with orll.( )1%may produceadistmct and durable effect, though ganic hydroxy compounds (alcohols or phenols) or, for it IS also poss ble to use an amount of up to about 2%. example with the use of thionyl chloride, converted into The new th ophene derlvatives acting as bnghteners may carboxylic acid chloride groups and the latter by treatalso be used in the following Ways: ment with ammonia or primary or secondary amines into (a) In admixture With dyestuffs or pigments or as addicarbonamide groups. tives to dyebaths, printing, discharge or resist pastes.

The new thiophene derivatives of the composition Also for after-treating dyeings, prints or discharge effects. state a more or less strongly pronounced fluorescence. (b) In admixture with chemical bleaches or as additives They may be used for optically brightening a wide variety to bleaching baths. of materials, more especially organic materials. Good (c) In admixture with finishing auxiliaries, such as starch results are obtained, for example, in brightening acrylic or synthetically produced finishing auxilaries. The products of the invention may, for example, also be quers, for example acetylcellulose lacquers, or nitrocellu added to the liquors used to achieve an anti-crease lose ester lacquers. Above all, the new thiophene derivfinish. atives are suitable for optically brightening synthetic (d) In combination with detergents. The detergent and I already contain a proportion of the brightener. Suitto yield about 330 parts of the compound of the formula I A r 6 the brightener may be added separately to the washing melting at 251.5 to 253 C. 600 parts of this compound liquor. It is also of advantages to use detergents that are stirred with 10 parts of boric acid in 2500 parts by volume of diethylene glycol diethyl ether. The solvent able detergents are, for example, soaps, salts of sulfonate is then evaporated dropwise, together with the corresponddetergents such, for example, as sulfonated benzirni- 5 ing amount of water of reaction, under nitrogen and atdazoles substituted at the Z-carbon atom by higher alkyl mospheric pressure in the course of 4 hours. The clear, radicals, furthermore salts of mono-carboxylic acid dark melt obtained in this manner is allowed to cool, then esters of 4-sulfophthalic acid with higher fatty alcohols; pulverized and dissolved in methylene chloride. The dark also salts of fatty alcohol sulfonates, alkylarylsulfonic solution is filtered through five times its quantity of acacids or condensation products of higher fatty acids 10 tivated alumina, evaporated to dryness and the residue is with aliphatic hydroxysulfonic or arninosulfonic acids. crystallized from ethyl acetate. After drying, there' are Further suitable are non-ionic detergents, for example obtained about 240 parts of the compound of the formula an? H300 v V Sv \0 00113 in the form of small yellowish needles melting at 146- 151 C. After repeated recrystallization from benzene the compound melts at 150 to 151 C.

polyglycol ethers derived from ethylene oxide and higher fatty alcohols, alkylphenols or fatty amines.

When the present process is combined with other treatment or improvement operations, it is of advantage to Analysis: OZUHZQNiOfiS C H N perform such a combined treatment with the aid of suitable preparations. These stable preparations are distin- Calculated, percent. 7 63.66 4.52 5.71 guished by the fact that they contain compounds of the Fmmd'percem 6M0 above Formula 1 as well as dispersing agents, detergents, 3O dyestulfs, pigments or finishing auxilaries. V

The compounds of the above Formula 1 may also, be applied after having been fixed on a finely dispersed vehicle. t

Unless otherwise indicated, parts and percentages in the following examples are by weight.

The compound of the Formula 13 is suitable for use as optical brightener for polyamides, for example nylon.

When in the process described above thiophene-2z5- dicarboxylic acid chloride is replaced by 3:4-dimethylthiophene-Z:S-dicarboxylic acid chloride, and the con.-

.densation is performed in identical manner, there is obtained the compound of the formula I (14) H3O CH .N a N7 emorncoocrr, \S( \y()/ CH OOCCHgCHF in similar purity and yield in the form of small yellowish Example needles from benzene, melting at 156 to 157.5" C.

390 parts of 4-hydroxy-3-amino-1-(2-carbomethoxyethyl)-benzene are. stirred below 20 C. portionwise into Analysis: flfi flflNfl fi O H N a solution of 209 parts of thiophene-Z:S-dicarboxylic acid dichloride in 4500 parts by volume of anhydrous toluene. a ulat d, perc nt 64. 85 5. 05 5. 40 The grey suspension is heated to the reflux temperature, Fmmdpemm 64'87 whereupon a strong evolution of hydrochloric acid is observed. When hydrochloric acid is no longer being when in the Process desfibed above 4-hydroxy-3- amino-l-(2-carbomethoxy-ethyl)-benzene is replaced by 4-hydroxy-3-amino-l-cyanoethylbenzene, and the conbatch is suction-filtered and the residue rinsed with a small densallon 1S plerformed ldentlcal manner, thvrcompound amount of toluene. 4 of form After drying, there are obtained about 523 parts of a (15) yellowish green powder melting at 243 to 244 C. The i N He N crude product is dissolved in boiling dioxane and the NGCHzG 2 \C 3 1 evolved, 1500 parts by volume of toluene are evaporated, and the yellow-green suspension is cooled to 20 C. The

CHzCHzCN solution is filtered, concentrated and allowed to cool. The reaction mixture is suction-filtered and the residue dried,

O 0 H20 Hris obtained in a similar yield and purity in the form of Example 4 small yellowish needles from dioxane, melting at 243 to 244 C 7.4 parts of the compound of the Formula 13 are stirred with 25 parts of ethanolamine. When the mixture is heated to 150 C., there is first formed a clear solution Analysisl CZ4HIBN4O2S O H I N from which after a short time the reaction product separates out. The whole is stirred on for one hour at 150 ggh g gg lgg 3% 2g 5g C., then cooled to room temperature, stirred with 25 parts by volume of acetone, the yellow crystal magma is suctionfiltered and rinsed on the filter with acetone. After dry- Example 2 ing, there are obtained about 5.2 parts of the compound A mixture of 190 parts of the compound of the Formula of the Formula (18) o N N 0 jc-cnrcntfi fi GHzOHnOi HOCHzCHzNH HNCH:CH:OH 0 S \O 13, 4500 parts by volume of methanol and 1080 parts of melting at 275 to 276 C. On recrystallization from disodium hydroxide solution of 30% strength is refluxed for m hy1f0rmamide+ethanol there are obtained small light- 48 hours. The suspension is diluted with Water, rendered Yellow needles melting at 276 f0 7 C.

acid to Congo red with hydrochloric acid and the methanol is evaporated. The precipitate formed is suctioned off Analysls: CMHHNtOtS C H N and crystallized from glacial acetic acid, then suctioned ZClcltd, t 1.0 14 .2 oil? and (llled, to yield about 142 parts of the compound 0 F mi d j 1.36 3 17 i8. 1( of the formula o om-omin the form of pale-yellow flakes melting at 283 to 285 C. The diamide of the dicarboxylic acid of the Formula 16 After repeated recrystallization from glacial acetic acid 35 is obtained in a similar reaction by treating the diester the compound melts at 286 to 287 C. compound of the Formula 13 with an excess of ammonia in ethyl alcohol.

Analysis: CzlHrsNzOsS C H i N Example 5 O 3 A mixture of 7.4 parts of the compound of the Formula %3u l? ll???l::::::::::::::::::::::::: :38 333% 3:33 13, Parts by j/Olume of dioxane and 10 Parts of drazme hydrate is heated to the reflux temperature. On

The compound of the Formula 16 is suitable for use as optical brightener for polyarnides.

Example 3 2 parts of the compound of the Formula 16 are suspended in parts by volume of water and 2 N-lithium hydroxide solution, 2 N-sodium hydroxide solution, 2 N- as a light yellow powder melting above 350 C. The analytically pure product is obtained from much dimethyl formamide as a finely crystalline powder.

potassium hydroxide solution or 2 N-ammonium hydroxide solution or triethanolamine solution of 10% strength is added until a clear solution of the corresponding dialkali metal salt or di-ammonium or di-triethanolamine salt of the dicarboxylic acid of the Formula 16 has Analysis: oztnflN ots o 11 formed. At an elevated temperature about 15 parts by volume of 2 N-barium chloride solution are added drop- Calculated, percent 58. 70 4,52 wise, whereupon a yellow precipitate is formed spon- Foundpment 53'95 taneously. The whole is cooled to room temperature, suction-filtered, and the filter cake is Washed with water Example 6 and dried, to yield about Parts Of the compound of 10,000 parts of a polyamide, prepared in known manner the Formula from hexamethylenediamine adipate, in chip form are in the form of a yellow powder.

ongomcoopg mixed with 30 parts of titanium dioxide (rutile modifica- 9 10 tion) and 10 parts of the compound of the Formula 13 or Example 9 15 in artumblel' fr 12 hours- T 19 t t n h A soap (sodium salt of higher fatty acids) is prepared manner are melted 111 a Vessel heated Wlth Oil Vapour which contains 0.05% of the compound of the Formula diphenyl vapour at 300 to 310 C., from which the at- 1 mospheric oxygen has been expelled y means of SHPBF 5 Acetate rayon or cotton washed for 30 minutes at 60 heated Steam, and then Stirred half an h C. with such a soap has a brighter aspect than material 18 then expressed through a Splmlerelr Imdfl a nitrogen washed with a soap that does not contain the compound of pressure of 5 atmospheres (gauge) and the resulting, the, Formula 18. i cooled filament is wound on a spinning bobbin. The fila- What is claimed is: ments produced in this manner display an'excellent bright 1. A compound of the formula wherein X is selected from the group consisting of (a) carboxy (b) cyano (c) carbo(lower)alkoxy (d) carbarnyl (e) hydroxy(lower)alkylcarbamyl (f) carbohydrazide X-1ower alkylene l lower alkylene-X ening effect which is fast to heat-setting and of good fastness to washing and light.

Example 7 A bleached woven fabricof polyamide staple fiber yarn is treated at a goods-to-liquor ratio of 1:30 for half an hour at 40 to 90 C in a bath containing 0.1% (of the (g) c weight of the fiber material) of the compound of the (h) Formula 15 or 16 and 1 cc. of acetic acid of 40% strength (i) COOLi per liter. 'COOBa After having been rinsed and dried, the'fabric so treated (j Y has a higher white content than it had before the treat men (k) C0OH-NH and (l) COOH-N(CH CH OH) and Z is selected from the group consisting of hydrogen and methyl.

2. The compound of the formula N N No-oI-n-om E E aurora-0N o- *0 S Example 8 A melt of 1 00 parts of polyester (polyterephthalic acid ethylene glycol ester) and 0.05 part of the compound of the Formula 1 3 is expressed through a spinneret to form a tape. The polyester tape produced in this manner has 5. The compound of the formula 6. The compound of the formula 7. The'compound of the formula a substantially higher white content than one that does not contain the thiophene compound.

H 0 0 O C-CH2--CH HOCHrCHz 12 8. The compound of the formula References Cited in the file of thfs patent UNITED STATES PATENTS 2,995,564 Duennenberger et a1. Aug. 8, 1961 FOREIGN PATENTS 211,167 Australia Oct. 24, 1957 Attest:

" UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0, 3 136 773 June 9 1964 Erwin Maeder et 61,

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Columns 9 and 10 claim 7 the thiophene moiety at the center of the formula should appear as shown below instead of as in the patent:

Signed and sealed this 10th day of November 19640 (SEAL) ERNEST w. SWIDER EDWARD J. BRENNER Attesiing Officer Commissioner of Patents 

1. A COMPOUND OF THE FORMULA 